Vessel occlusion is often necessary in a variety of cases including but not limited to treatment of aneurysms, atrial septal defects, patent foramen ovale, left atrial appendage occlusion, patent ductus arteriosis, fistula, arterio-venous malformations, fallopian tube occlusion for the purposes of sterilization, and occlusion in the peripheral vasculature. One method of treatment involves insertion of an expansile material, such as hydrogel, for occlusion. Hydrogel is an expansile, hydrophilic polymer. Hydrogel can be incorporated in embolization coils or can be injected independently. Hydrogel typically expands when exposed to material, such as blood. This response is based on the pH of the material the hydrogel is exposed to. The hydrogel or hydrogel-containing implant has a contracted form during deployment, and adopts an expanded form suitable for occlusive purposes after exposure to blood. During interventional procedures, the working time for introducing and deploying hydrogel or a hydrogel-containing implant is relatively low due to its expansile properties. A method of controlling hydrogel expansion would thus be beneficial to extend working time during interventional procedures. Alternatively, a method of augmenting hydrogel expansion would be beneficial to enhance the space filling properties of the hydrogel or hydrogel-containing implant.
Broadly, a system and/or method to control contraction and/or expansion of a hydrogel could aid in interventional procedures.